Gas-assist analysis simulates the gas-assist injection molding (GAIM) process. Nitrogen gas injection enhances melt-front advancement and packing. This results in cored areas of the part and improved part quality.
Common applications are handles or other parts with thick areas such as automotive door panels. It is also used to reduce clamp tonnage on parts with large projected area.
Three methods are used: short-shot, overflow wells (spillover) and structural web.
3D Shapes has been providing gas-assist analysis since our first projects with Safety 1st in 1996. We developed expertise with gas-assist methods by working with industry experts and an expanding base of clients. At the time, C-MOLD had the best gas-assist simulation capabilities and we added that module to expand our offerings.
Over the years, the simulation tools have become more capable, easier to use and more accurate.
Gas-assist is effective in hollowing out thick geometry, such as handles, or to improve flow and decrease clamp tonnage requirements on large parts. Moldflow analysis will provide valuable insight.
Patents for overflow wells expired many years ago. Prior to that their use was discouraged. Now they are routinely used since they tend to allow a more stable process.
With gas-assist, a little analysis and outside expertise can save your project from unwelcome surprises.
3D Shapes contributed the analysis chapter for this excellent reference by Bauer Plastics Technology Group.